Pulp-testing device



Aug. 3 ,1926; v 1,594,941

A.- B..GREEN y PULP TESTNG DEVICE Filed Dec. 2, 1921 PATENT OFFICE.

ARTHUR BROOKS GREEN, OF LINCOLN, NEW HAMPSHIRE.

PULP-TESTING- DEVICE.

Application led December 2, 1921. Serial` No. 519.568.

My invention relates to an apparatus for testing the draining capacity of dierent kinds of paper pulp with a view of deter-L mining the characteristics of the resulting paper. This has been done by placing the sample of paper stock in a chamber or ves sel having a pervious drainage bottom and measuring the amount of water which drains olf in excess of a standard rate of drainage.

Apparatus designed on this principle has not been successful for various reasons, among them being the fact that the preliminary stirring given to the l stock befre drainage was liable to charge the sample with air and also because there was no delinite and standard starting point where the drainage began to take place.

According to my invention, I provide a chamber with a pervious drainage bottom or outlet with an air tight cover to hold back the commencement of the drainage action and a vent opening preferably through the air tight cover for admitting air above the pulp so 'that drainage can be started as deslred at a standard and definite point or when the stock has been properly beaten.

Other important features of my invention will be pointed out in the appended claims.

The figure of the drawing represents a vertical section through the pulp-holding receptacle and the receiving funnel with a side elevation of the measuring receptacle at the bottom.

Referring to the drawing, 1 represents a chambeiior drum open at the top and bottom but capable of being closed air tight by a hinged cover 2 at the top and 3 at the bottom, both covers being provided with suitable gaskets for formlng tight joints with the ends of the chamber.

The lower end of the chamber is closed by a pervious drainage 'bottom 4 secured in place by a suitable ring 5. The cover 3 fits over the lower end of the chamber enclosing the drainage bottom 4. The cover 2 is clamped in place by a clampY 6 and the cover 3 is clamped in place by a clamp 7 of well known construction.

For the purpose of venting the space above the pulp, a petcock 8 is placedlin the cover 2 to admit air when it is desired to start the drainage.

The drainage is caught by a funnel 9 placed beneath the chamber and the water is dschar ed through a standard opening 10' at the ttom of the funnel. A short distance above the' opening 10 is a lateral duct l1 Yfor conveying off the water which accummulates above the outlet when the drainage is more rapid than the capacity of the-opening 10.

A hood l2 is placed above the inner end of the duct' 11 so that none of the descending liquid will enter the duct l1 which is only designed to receive the overflow from the body of liquid collecting above the outlet 10.

The liquid flowing off from the duct 1l is collected and measured in a graduate 13.

In operation, the lower cover 3 is closed, the standard sample of pulp stock is poured into the chamber, the upper cover being open.v The stock is now thoroughly stirred until the 'surface is of a creamy consistency and then the cover 2 is closed with the pet cock 8 open.

The pet cock is` now closed so that the upper end of the chamber will be hermetically sealed.

The lower cover 3 is now dropped down and pened leaving the drainage bottom expose No drainage, however, will take place owing to the air 'tight cover 2 being closed until the pet cock 8 is opened for the purpose of starting the drainage.

It will thus be seen that the drainage is started in each sample after the stock is thoroughly stirred and after the drainage once begins, the stock is undisturbed until the operation is complete.

The conditions under which the drainage takes place `in veach sample are thus exactly alike and a very accurate test of the drainage capacity cfu the pulp may be made by the use of my apparatus.

1. A device for testing pulp comprising, in

combination, a xed vessel having a pervious bottom and a removable cover therefor, and having a top openingthrough which the pulp can be inserted and thoroughly mixed by stirring; a closure for said top opening having a valved inlet; and means below said bottom adapted upon the removal of said bottom cover and the opening of said valved inlet to receive the drainage through said pervious bottom; said means comprising a funnel-shaped receptacle having a bottom outlet of predetermined dis' charge capacity; a second outlet through the wall of thereceptacle having its opening guarded against direct reception of the drainage and arranged to discharge by over- How the drainage in excess of that passing through the bottom opening; and means to collect the drainage discharged through said second outlet.

2. A device for testing pulp comprising, in combination, a fixed vessel of relatively large cross section having top and bottom openings; a pervious screen across said bottom opening; a removable cover for closing said-bottom opening and retaining the pulp in said vessel to permit stirring of the pulp through said top opening; a closure for said bottom; a receptacle below said vessel for receiving the drainage through said bottom, having an outlet of predetermined size for wastage of a portion of said drainage, and having a second outlet above the outlet of predetermined size, whereby the drainage in excess of said wasted portion vaccumulating and rising to said second outlet may be discharged, and means for'collecting said ydischarged excess, there being a guard in said receptacle above the second outlet preventing direct admission of the falling drainage into said second outlet.

et. The method of testing pulp which consists in temporarily holding the charge to be tested in an open fixed vessel having aA pervious bottom temporarily closed 'and while thus closed stirring the pulp with its surface exposed to free atmosphere, then sealing the top ofthe vessel and opening the bottom closure, admitting air to the vessel above the stirred pulp, whereby drainage of water therefrom occurs, and collecting said drainage discharged in excess of a predetermined rate.

'ARTHUR BRooKs GREEN. 

